I think the 2.5 model, with the whiz-bang cooling and new chips, is the first next-gen G5, whereas the lower models are designed to clear out old supplies. November will see the real "bump" to 2.5/2.7/3.0 all-liquid series.

Here's a theory: The 2.5 is slated to start shipping in July, so maybe Apple is getting around the new-model-launch-delays bear? Will they announce and ship the "missing" 2.7 and 3.0 portions of the range in September, when they would have shipped anyway, even if they were announced today? "Clearing out the old machines and releasing the typical low-end 'shipping today' portion of the new model range, and keeping mum on the parts we would normally delay two months."

That said, they are still impressive machines, save for the GPU. Also, to the first poster, the top end chips are 2.5Ghz, not 1.5...

I like the idea of liquid cooling but I also like simple systems. There's too much complexity here. So...

I've often pondered creating a sealed aluminum case with integrated heatsink. Stick the components in and fill it with dielectric oil in order to create a huge, passive heat sink (like a big transformer or whatever). Thoughts? I almost got around to this but stopped after submerging an old hard drive in some dielectric - if you seal the breating hole, it works fine (I believe the hole is there to relieve pressure differentials caused by changes in altitude so it should be fine in a stationary location).

Provided that the dielectric has good enough heat transfer, this should work, no?

I do (very) high end post production for a living and I wanted to replace my G5s with the new machines because I needed internal RAID arrays of more than 2 drives. Two drives will not give you the bandwidth you need for HD or digital cinema formats. I can't use solutions like WiebeTech's G5 Jam because my full length PCI cards take up the space.

I looked on the web site and it looks like the new machines didn't put in new drive bays in front of the CPUs (as was mentioned on some rumor sites). Am I wrong? Is there a way to add more drives?

I'm surprised that the 2 new offerings from Apple were simply put out on the web without any Steve Jobs fanfare. I like it when Steve shows it first, he allows into his RDF. I guess overall it's not the update I was hoping for, the video card should have been upped as well.

I think it's pretty safe to say we're gonna have an all new iMac at WWDC. It's the other upgrade everyone's been waiting for. Aluminum iMac? We'll see.

Difficult to tell from the article, but the liquid cooling system looks similar to that found in
Shuttle XPCs [overclockercafe.com]
The article says that OS X can vary the flow of the liquid though.
Very nice though, looks like they have thought about noise, which is good.

Actually, the one I saw the guy built a custom styrofoam cooler/case, put in all his goodies except the power supply, then filled it up with some odd and expensive 3m non-conductive liquid...actually I think he used mineral oil first, but that turned out pretty gooey... Then put in a pump and started pumping liquid from the bottom to the top where it dropped over a coolant radiator.

Yeah- that's a long way to go to attempt overclocking, but it was pretty neat.

IIRC, it ended up overheating anyway because the liquid got less viscous (more??--more solid) the colder it got, and created isolated thermal heat nodes around the hot components. Would've been cool to see on an infrared scope...

I like it when Jobs does his old "oh, and one more thing..." also. I think the WWDC will have something bigger than new G5s though. I'm guessing it will be bigger than a new iMac. With the release of AirPort Express and such, the low-fanfare announcement of the new G5s, but more importantly the setup of an entirely new division dedicated to the iPod, I'm guessing we'll see a new consumer product. You gotta love the rumors that fly around the Apple camp. I'm taking stabs at what the next unveiling will be also...but it sure is fun. New consumer product...hmmmm...

Well, IBM was the first to go on record as saying that 90nm was considerably more difficult to implement than they first expected. There's a lot of current leak going on, meaning wasted power, which leads to increased heat (see Intel's Prescott as a very good example). Supposedly AMD's having some 90nm issues as well now.

I guess those issues would explain why Apple had to switch to liquid cooling for this round of systems.

The details on this liquid cooling thing are a bit sketchy, but the diagram doesn't show a pump/compressor.

Is it possible that this is actually using heat pipe tech like that found in the newer shuttles? Namely, block attached to the CPU is linked to a large sink away from the processor, connected by pipes filled with conductive fluid. Large fan cools the radiator.

Net result is of course a complete lack of moving parts other than the (easily replaceable) fan(s). Of course, it doesn't cool as well as a full blown liquid setup, but then the PPC970's don't run *that* hot.

Anyone know any ore about this? Even if it's not entirely revolutionary, it's still interesting tech.

Wow, that's a sign of desperation. I've heard tidbits of information at the major tech news sites that although IBM boasts it can get to 3GHz on the PPC970 architecture, and that a G5's power consumption is very nicely low at 2GHz, that changes very quickly as the speed starts to ramp. The fact that they need watercooling stock to get to 2.5GHz seems to confirm this.

This is quite disturbing. It confirms the overall signs that photolithography scale shrinks aren't working anymore. I had thought that perhaps Intel's problems with Prescott were an isolated incident, but it doesn't seem so now. AMD has only just begun experimenting with 90nm, and now it appears that IBM, the only company so far to have said anything positive about their progress at 90nm, is having to (it would seem) overclock their chips and watercool them to get to a stable and quiet 2.5GHz..

I think I was more blown away with the side bar showing the internal design. Now I understand why the mac G5 is slightly bigger than a PC case and why macs dont have multiple front panel drive bays. there are clear front to back air channells. so air can trully be swept through in one pass. just look at that crammed pc case : it looks as useful as a square suace pan would be on you stove. the cpu fan vents in to a poorly stirred airmass. you cant even put output fans or input fans in logical places since all of the back is taken up with power supply and PXI car slots and the front is covered with drive bays. There are endless nooks and heaps of wire. and most of the air lives in a blob above the motherboard never in contact with it.

in contrast the mac case has layers of flowing air no thicker that what is probably the thermal diffusion length. Air flows over the top and bottom of the hotest items and does so in one pass. Its beautiful. and mac planned this out from the beginning for expandability.

The diagram is a little off unless the heat to color scale is non-linear.

It does bug me a bit that the things are shown in series. That means that one device will invariably be hotter than the other, assuming equal load. I imagine that they could set the affinity such that one CPU gets a job if there's little to do, the second CPU only gets a job when things get busy. Windows seems to try to balance them.

I've heard on Harley's V-Twins that it is almost always that if a cylinder goes bad, it is the back cylinder because the cooling air that reaches it is pre-heated by the front cylinder. Makers like Moto-Guzzi have the engine with the V facing forward, so they avoid that problem, each cylinder gets its own air.

ahhh but bundling up cables and actually designing the cable to be hidden are two different things.... even on the original B/W G3 you couldnt find a IDE cable anywhere, they ran under the motherboard and the case frame except in one spot where it was above

Nice speedbump - the new top-end dually is particularly nice. It's a pity that they couldn't get to the promised 3 GHz within the timeframe they planned, but a top end of 2x2.5 GHz with a bus speed of 1.25 GHz and PCI-X is still a pretty good box.

This should give a much-needed kick in the pants to Apple's Pro sales for a while. It'll be interesting to see what (and if) they show for hardware at WWDC, since we already had the G5 today and AirPort Express on Monday, with iTMS Europe next week.

If I had to guess, I'd say we'll get a G5 iMac now (maybe at 1.8 GHz), but I'm not too sure. It could turn out to be a software-only WWDC.

I'm no hardware engineer, but looking at this [akamai.net] artist rendering (akamai.net is an image host for all Apple.com images) of Apple's liquid cooling system [apple.com], I think the processors are getting different cooling.

It would appear that the liquid passes over processor #1, then #2, then back to the heat sink to be diffused by the fan blowing over it. This would say to me that processor #2 is getting at best room temp water cooling, while proc #1 is getting cold water cooling.

Here's my reasoning: If the heat sink with the fan blowing over it can cool the water 2X degrees, then when it is leaving the cooling system it is at Room Temp (RT) - X degrees. It passes over both processors and returns to the cooling system at RT+X degrees, where it is cooled by 2X and leaves the system at RT-X, headed for the hot processors again, follow?

So here's the meat of it: both processors together heat the water up by 2X (see above). That means each processor heats the water by X, so when the cool water leaves, it is at temp RT-X, passes over the heat sink and it raised to (RT-X)+X=RT which then passes over the second processor and cools it to RT+X where it returns.

So the second processor is getting room temp water cooling while the first is getting RT-X cooling. What effect will this have on the system?

I'll agree with that - I've been with NeXT->Rhapsody->OS X for a while now, and the G5 is the first workstation since the black slab with me want goodness included. Well, I briefly wanted an Ultra 5 but they became old hat quite quickly. I don't think the same will be true of any of the G5 systems:-)

Nine fans and 21 sensors, generating half as many decibels. Now I'm not an Apple fan-boy but that's the level of attention to detail that seperates Apple from Dell, etc.

Most Dell desktops are a fair sight quieter than the G5, from what I've seen (and heard). It's impressive that Apple got a computer that needs nine fans to be fairly quiet, but with most Dells, well, you only need two fans (one in the PSU and one over the CPU, with a plastic hood).

The PowerMacs are impressive for all sorts of other reasons, but saying "amazingly quiet for having nine fans" is progress seems backward to me. Same with the liquid cooling; it's only there because the G5 runs incredibly hot. I'm sure people will be touting liquid cooling as an advantage, when really I think it should be viewed as a necessary evil. Wouldn't it be better to use a processor that doesn't need to be liquid cooled??

For my applications un-optimised code on a 2 Ghz G5 runs about the same as on a 3 Ghz Pentium and a 2.4 Ghz Xenon, if I optimise the G5 code with xlf and shark I get my 2 Ghz G5 to run twices as fast as the Pentium or Xenon... but I don't have the intel compiler for the P4 or Xenon so that's not a fari comparison.

It IS beautiful, although I am left wondering whether it wouldn't be preferrable to have the air flow rising as it naturally tends to do. Some houses have been so well engineered that there is no HVAC system needed, all the circulation is passive... would it be possible to do this with a computer?

Well, here at work, we have a handful of Dell desktop machines and we were also the first on our block to get the dual 2Ghz G5. I can tell you for certain that the Mac is WAY quieter than these particular Dells (YMMV of course).

It's not so much that the Mac is amazingly quiet for having 9 fans, it's amazingly quiet for having any fans. They could definitely get away with 2 fans, but they'd have to run faster so they'd be louder.

The liquid cooling thing is all part of it...you know the kind of fans you're typically running on a new Intel/AMD chip? Well if you liquid cooled them like this Mac, you could probably get away with a much quieter setup. Again, I'm sure they could air-cool them, but they'd be loud like your typical PC.

It's not a really positive sign. It could also be a little on the over engineering side. I don't know that the need the water cooler, it could just be that they feel more comfortable with it.

I live in Boulder Colorado, the elevation at my home is 6500ft above sea level and the 2.8Ghz Dell Pentium IV I bought a couple months back is near the ambient temperature threshold as speced by Intel. If I run it in a non-AC house this July I'll probably be over the limit just because of the elevation and the heat around here. Intel references about 100 degrees F at the vent but that goes down a fair bit since the air here is more thin and can't disapate heat as well as the dense sea level air; I'm assuming the Dell builds close to the reference spec. So say it's 98 outside, no AC in the house but it's at maybe 80 degrees and then my dell tower is enclosed under my desk.

several words : If you're using hardware that only has OS9 drivers classic doesn't help. If you need to run OS9 audio/video apps, classic is too slow. Also, some people are happy with os9 and dont want to buy new app upgrades. For them, running OS9 natively makes far more sense.

As an aside, three word replies are really not very useful if you're tryin to make a serious point.

Think Secret is reporting that new displays are due soon [thinksecret.com]. The new displays apparently will be DVI only -- no more ADC. (The 30" display requires 150W, which ADC couldn't handle.)

What puzzles me is the GPUs currently in these new G5s -- they seem to be dual-head ADC+DVI. That's not terribly useful once ADC goes the way of the dodo. If you're in the market for the new displays, it might be worth holding off on the G5 a few weeks, in order to get a DVI+DVI video card.

Just my.02, I've always loved the idea of liquid cooling, but peltier coolers and all the mess associated with standard 'open' type systems where you have leaks has made me shy away.

With closed loop systems like this with some of the new thermofluids that are being developed are pretty exciting.

I wouldn't be amazed that with all the new processors and heat issues you won't see more of this type of cooling in Intel applications.

take a look at the http://www.thermacore.com/thermaloop.htm site, they've got a ton of animations on what they're doing with this type of technology. And they're already moving stuff around for a lot of companies.

Did that include the cost of the OS and equivalents of all the other software goodies in the Apple package? Or all the nickel and dime extras you need for a PC that come with a Mac. And I can't be too surprised when you compare a single processor system with a dual processor system and then declare the single processor to be less expensive. And when you say the single processor system is faster you may be technically correct, but I wonder if it will do more work; which is what really matters imho.

The myth that Apple is more expensive is just not true, as anyone who has done a serious comparison of features will tell you.

I happen to have three Athlon 64 systems and two G5 systems. I spend time on all of them as a mercenery for hire, but I believe that I'm most productive for my non-professional work on the Mac, which is where I put all my personal stuff.

If you want the machine, buy it and upgrade incrementally. There's no law that says that the second you buy your machine you have to load it up with memory and disk.

My dual 2ghz G5 performs great with the stock 512mb RAM. I've upgraded it to 3.5gb, and there is a difference (mainly in switching applications), but the system with its stock RAM configuration is perfectly usable.

My 160gb system disk lasted about 8 months before I had to buy a new 250gb to fit the empty slot. I would have gained nothing by buying the 250g disk with the system.

Apple makes fantastic computers, and I'm a fanatical Apple loyalist -- but you'll get everything cheaper if you go to Fry's(*) or shop on the net for components like memory and disk. Memory upgrades are universally about triple the going rate if you get them from Apple, and Apple's brilliant case design makes them easy to install.

Always upgrade incrementally. It will let you spread the financial pain and you'll enjoy getting the performance boost treats spread over time.

Hope that helps.

D

(*) If you're not in California, you may have never heard of Fry's. It's a huge retail store, designed by scions of a prominent supermarket family, that works basically like a supermarket for computer gear. If it exists, and it has to do with computers or salty snacks, it's probably hiding somewhere in Fry's, waiting patiently for you to discover it.

The myth that Apple is more expensive is just not true, as anyone who has done a serious comparison of features will tell you.

Sorry, but it used to be true. The G5's are the first systems Apple offered that are a reasonable deal compared to PC's. Honestly, I'd like to see a $1000 machine based on a 1.6ghz G5. Then Apple would really turn some heads.

And Apple monitors, while excellent, are still too pricey. They need a $400 17" DVI-D only model or something.

Look at the iMacs... a 1ghz G4 with a 15" LCD for $1300? I could get a MUCH faster Athlon64 system for that with more RAM and disk space, plus it would be upgradable.

Yeah, you're paying for the software and the "experience", but frankly, most people don't care enough to plunk down the extra cash, and they still have to pay another $200 (or more) for MS Office when cheaper PC's come with it for free.

If I'm lucky, I'd walk away paying $4500. I'm also an Apple Developer, so I'd get another discount there, or buy through work for being an Apple parnter for science and research facilities, so let's say $4000. I paid $1600 TOTAL last time around. Yikes.

Yeah, okay I could finance the monster out for as long as 5 years, which is just totally insane. I've had my iMac for 2 years and I'm already looking at getting rid of it, so financing at the best possible interest rate Apple offers would for 24 months comes out to $192/mo. For a computer. People pay that much for a CAR or even other people to put a roof over their heads. My wife would kill me if I didn't have the cash saved up ahead of time, and if I did, she'd say there are far better things for me to spend my money on.

Look at how even 2.5GHz has to be liquid-cooled to be stable enough with the old transistor fabrication process.

What's wrong with liquid cooling? It is the future of computing. Fans are good but Apple is really trying to change the personal computer. What they do design-wise and technology-wise usually influences the overall computer market (e.g., end of floppy drives; WiFi; 64-bit processors). Apple is breathing life into computers (although IBM could just make more efficient processors that don't put off as much heat but eventually we will need liquid cooling or something other than just fans to keep our computers cool).

I think trying to judge the system by an artist's drawing (even in Apple's own materials) is not going to lead to any definite conclusions. Certainly the hardware engineers understand the issue you raise. Almost as certainly the artist understands that reducing the complexity of the drawing to make it more visually appealing and easier for the 'unwashed masses' to understand is more important than being technically correct.

To that you'd have to add the cost of your time to assemble it and install software. I don't know about you, but my consulting rate is high enough that the Mac is already cheaper when assembly time is factored in.

Unless you enjoy building computers from scratch like I do. It's relaxing and interesting to work with computer innards at times.

However, I have enough old PCs laying around for that fetish, but some people prefer building their own to buying.